1. Field of the Invention
This invention relates to a hydraulic reservoir for tandem master cylinder, and more particularly to a hydraulic reservoir for tandem master cylinder for a vehicle braking system having at least two braking circuits.
2. Description of the Prior Art
Generally, two separate brake fluid pressure generating chambers are formed in the interior of a tandem master cylinder. Two hydraulic reservoirs are mounted on the tandem master cylinder in order to supply brake fluid into the two separate brake fluid pressure generating chambers. However, recently one hydraulic reservoir having two outlets has been used for supplying brake fluid into the two brake fluid pressure generating chambers of the tandem master cylinder.
The hydraulic reservoir having two outlets includes a body formed by upper, lower and side walls, two brake fluid reserving chambers formed by partitioning members in the body and passages which make the two brake fluid reserving chambers communicate with each other at a predetermined level, and as occasion demands, a fluid level sensor for warning the driver of the impermissible reduction of brake fluid.
It is required for the above described hydraulic reservoir that, when the automobile runs on the inclined roadway, such excessive brake fluid flow does not occur between the brake fluid reserving chambers that brake fluid is one-sidedly received by one of the brake fluid reserving chambers, and the fluid level sensor erroneously operates.
When a brake fluid conduit connected to the one brake fluid pressure generating chamber of the master cylinder is damaged or cracked by springing stones, brake fluid gradually leaks out through the cracked portion of the brake fluid conduit, and the one brake fluid pressure generating chamber connected to the damaged brake fluid conduit from the corresponding brake fluid reserving chamber. Finally, the brake fluid decreases in the corresponding brake fluid reserving chamber so much that wheels for the damaged brake fluid conduit connected to the one brake fluid pressure generating chamber cannot be braked. In such a case, it is required that a sufficient brake fluid to brake the automobile is always reserved in the other brake fluid reserving chamber.
The reservoir for tandem master is connected to two inlets of the tandem master cylinder. Accordingly, the reservoir is long in the axial direction of the master cylinder. Particularly, when any other part such as filter is arranged in the reservoir, the latter becomes longer. More brake fluid between the brake fluid reserving chambers flow in the longer reservoir, when the latter is inclined.